> On 8 Oct 2021, at 15:53, Linus Torvalds <[email protected]> wrote: > > On Fri, Oct 8, 2021 at 11:50 AM Attilla de Groot via subsurface > <[email protected]> wrote: > >> Logging: >> - Subsurface doesn’t understand the concept of a travel gas that well (it >> switches with the back gas). > > Heh. That example dive looks _very_ different from anything I ever did > in Bonaire.
My dives this week are quite exceptional indeed. Next week I’ll just do some recreational and looking at fish. :-P > > But your data clearly has > > <cylinder size='22.2 l' workpressure='232.0 bar' description='D12 > 232 bar' o2='14.0%' he='49.0%' depth='65.378 m' /> > <cylinder size='4.1 l' workpressure='206.843 bar' description='AL40' > start='220.0 bar' end='140.0 bar' depth='103.075 m' /> > <cylinder size='5.547 l' workpressure='206.843 bar' > description='AL40' o2='51.0%' start='200.0 bar' end='140.0 bar' > depth='21.021 m' /> > <cylinder size='5.547 l' workpressure='206.843 bar' > description='AL40' o2='79.0%' start='175.0 bar' end='90.0 bar' > depth='10.016 m' /> > > <event time='0:02 min' type='25' flags='1' name='gaschange' > cylinder='0' o2='14.0%' he='49.0%' /> > <event time='3:26 min' type='25' flags='2' name='gaschange' cylinder='1' /> > <event time='30:32 min' type='25' flags='3' name='gaschange' > cylinder='2' o2='51.0%' /> > <event time='44:40 min' type='25' flags='4' name='gaschange' > cylinder='3' o2='79.0%' /> > > which I agree is insane - you are going down to 82m and subsurface > thinks you're breathing air at the deepest point (and breathing that > hypoxic 49% He at the beginning shallow part). > > That would be unhealthy and bad if real. I agree that clearly the two > first gases are switched. > > However, subsurface thinks that because those are the gas switch events we > got. Is it possible to manually change this to how it should be (given that you’re explaining it must be a download/libdivecomputer issue)? I messed around with it a bit, but I don’t really understand the relation between the cylinders and gas changes in the XML. I haven’t been able to make it any better unfortunately. > And I have to say, when I tell subsurface to use the same 55/85 > Buehlmann settings that your dive computer reports it is using, the > deco that subsurface calculates isn't actually that far off from what > your Teric calculated. In fact, if anything, your Teric gave _more_ > deco at the end. > > That said, that can't be real, and I suspect the issue is that I only > see the one dive, and you presumably had some pre-existing deco > loading, and then subsurface getting the gases wrong just happens to > result in a fairly similar deco profile. That is fine, should I see it again sometime, I’ll bring it up separately. > I'll think about this a bit more to see if I can come up with > something, but I hope I have explained why it can be hard due to > libdivecomputer explicitly making it hard. Thank you, much appreciated. — Attilla _______________________________________________ subsurface mailing list [email protected] http://lists.subsurface-divelog.org/cgi-bin/mailman/listinfo/subsurface
